As negotiators headed to Copenhagen in December 2009 to forge a global climate pact, concerned U.S. business leaders and liberal luminaries took out a full-page ad in the New York Times calling for aggressive climate action. In an open letter to President Obama and the U.S. Congress, they declared: “If we fail to act now, it is scientifically irrefutable that there will be catastrophic and irreversible consequences for humanity and our planet.” One of the signatories of that letter: Donald Trump.

Also signed by Trump’s three adult children, the letter called for passage of U.S. climate legislation, investment in the clean energy economy, and leadership to inspire the rest of the world to join the fight against climate change.

“We support your effort to ensure meaningful and effective measures to control climate change, an immediate challenge facing the United States and the world today,” the letter tells the president and Congress. “Please allow us, the United States of America, to serve in modeling the change necessary to protect humanity and our planet.”

In every conceivable way, the letter contradicts Trump’s current stance on climate policy. On the campaign trail, Trump has said he is “not a big believer in man-made climate change.” Last fall, after Obama described climate change as a major threat to the United States and the world, Trump said that was “one of the dumbest statements I’ve ever heard in politics — in the history of politics as I know it.”